A physician wishes to prepare a buffer solution at ${\rm{pH}} = 3.58$ that efficiently resists a change in ${\rm{pH}}$ yet contains only small conc. of the buffering agents. Which one of the following weak acid together with its sodium salt would be best to use?

Acetoacetic acid $\left( {{\rm{p}}{K_a} = 3.58} \right)$

$m - $ chloro benzoic acid $\left( {{\rm{p}}{K_a} = 3.98} \right)$

$p - $ chlorocinnamic acid $\left( {{\rm{p}}{K_a} = 4.41} \right)$

$2,5$-dihydroxy benzoic acid $\left( {{\rm{p}}{K_a} = 2.97} \right)$

NEET UG CHEMISTRY MCQ: Equilibrium

1 Medium

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Application +4 | -1

A physician wishes to prepare a buffer solution at

\mathrm{pH} = 3.58

that efficiently resists a change in

\mathrm{pH}

yet contains only small conc. of the buffering agents. Which one of the following weak acid together with its sodium salt would be best to use?

View answer and explanation

Correct option: D

Acetoacetic acid

\left( {\mathrm{p}{K_a} = 3.58} \right)

The correct answer is D (Acetoacetic acid (pKa = 3.58)) because the best buffer is one where the pKa is closest to the desired pH.

Practice All Chapter MCQs →

Mg{(HC{O_3})_2}

MgC{O_3}

Mg{(OH)_2}

MgC{O_3}

K_{\mathrm{P}}

\mathrm{CaCO}_3

4.5 \times 10^{-2}

\mathrm{C}(\mathrm{s})+\mathrm{CO}_2(\mathrm{g}) \rightleftharpoons 2 \mathrm{CO}(\mathrm{g}),

K_{\mathrm{P}}

2.0 \mathrm{~atm}.

\mathrm{CaO}

\mathrm{CaCO}_3

+

\leftrightharpoons

\mathrm{PC}{\mathrm{l}_5}\leftrightharpoons\mathrm{PC}{\mathrm{l}_3} + \mathrm{C}{\mathrm{l}_2}

{K_{\mathrm{eq}}} = 0.41

\mathrm{p}{K_a}